洪水预报过程的交互式修正技术研究

由于预报模型的局限性和实时信息的不完善,洪水预报过程存在许多误差,而基于图形交互式修正技术是消除预报误差的有效手段。分析了水文预报过程交互式修正技术在洪水预报工作中的重要性,介绍了过程拟合平滑技术和样条插值技术,基于此基础上研究实现了以橡皮筋形式交互式修正水文预报过程的技术,并应用于洪水预报系统中。研究实例表明,该技术使用方便,有效地提高了洪水预报精度。     

MERLIN: a flood hazard forecasting system for coastal river reaches

Natural Hazards - This study presents MERLIN, an innovative flood hazard forecasting system for predicting discharges and water levels at flood prone areas of coastal catchments. Discharge...     

Development of roughness updating based on artificial neural network in a river hydraulic model for flash flood forecasting

Flood is the worst weather-related hazard in Taiwan because of steep terrain and storm. The tropical storm often results in disastrous flash flood. To provide reliable forecast of water stages in rivers is indispensable for proper actions in the emergency response during flood. The river hydraulic model based on dynamic wave theory using an implicit finite-difference method is developed with river roughness updating for flash flood forecast. The artificial neural network (ANN) is employed to update the roughness of rivers in accordance with the observed river stages at each time-step of the flood routing process. Several typhoon events at Tamsui River are utilized to evaluate the accuracy of flood forecasting. The results present the adaptive n-values of roughness for river hydraulic model that can provide a better flow state for subsequent forecasting at significant locations and longitudinal profiles along rivers.     

河道洪水实时概率预报模型与应用

通过数据同化方法合理地将实时水文观测数据融入到洪水预报模型中,可提高洪水预报模型的实时性和精确度。选取沿程断面流量、水位和糙率系数作为代表水流状态的基本粒子,以监测断面实测水位数据作为观测信息,建立了基于粒子滤波数据同化算法的河道洪水实时概率预报模型。模型应用于黄河中下游河道洪水预报计算的结果表明,采用粒子滤波方法同化观测水位后,不仅可以直接校正水位,同时也可以有效地校正流量和糙率,为未来时刻模型预报计算提供更准确的水流初始条件和糙率取值区间,进而有效地提高模型预报结果的精度,给出合理的概率预报区间。不同预报期的预报结果表明,随着预报期的增长,同化效果减弱,模型预报结果的精度会有所降低,水位概率预报结果受粒子间糙率不同的影响不确定性增加,而流量概率预报结果受给定模型边界条件的影响不确定性降低。所提出模型可以有效同化真实水位观测数据,适合应用于实际的洪水预报工作中。     

Determination of the distribution of flood forecasting error

Natural Hazards - Flood forecasting plays an essential role in enhancing the safety of residents downstream and preventing or reducing economic losses. One critical issue in flood risk assessment...     

实时洪水预报综合修正方法初探

利用误差的相似性扩大实时修正信息量,结合神经网络异联想记忆技术,提出了综合实时修正方法。并在七里街流域用11场洪水分别采用自回归(AR)模型和综合修正方法进行实时修正。分析结果表明,采用综合修正方法既能获得比AR模型更好的精度,又不损失洪水预报的预见期。进一步对闽江的6个支流流域近50场洪水进行综合修正方法实时修正检验,都获得了较好的结果。     

Uncertainty analysis of HEC-HMS model using the GLUE method for flash flood forecasting of Mekerra watershed,Algeria

In this paper, the lumped quasi-distributed hydrological model HEC HMS is used to simulate the rainfall–runoff process of the Mekerra watershed, located in the northwest of Algeria. The model parameters’ uncertainty and the predictive intervals were evaluated with the generalized likelihood uncertainty estimation (GLUE) approach. According to the results, good simulations were obtained with different values of variables for many sets of parameters generated randomly by the Monte Carlo procedure, which is known as Equifinality. After the analysis, only the hydraulic conductivity at saturation parameter appears well defined, taking values within a limited range. In addition, results indicated that combinations of likelihood measures associated with multiple and different periods of observations reduce a posterior uncertainty of estimated parameters and predictive intervals in some degree. Overall, the GLUE analysis showed that there is a significant uncertainty associated with hydrological modelling of watershed Mekerra, to a great extent due to multiple sources of errors.     

Designing a flood forecasting and inundation-mapping system integrated with spatial data infrastructures for Turkey

Turkey currently lacks a fully functional flood forecasting system (FFS). However, the studies necessary for establishing such a system are still being performed by the Turkish State Meteorological Service. The main purpose of this study was to determine the technical architecture of the FFS intended to be developed in Turkey and to design a flood forecasting and inundation-mapping system integrated with spatial data infrastructure (SDI). Because SDIs provide interoperability among the institutions by enabling collective use of data and services, this enables decision makers to take correct and rapid decisions regarding the forecasting. In the design of the system, the Web services architecture presented by the open geospatial consortium that develops international standards for SDI realizations was taken as a basis. Designed with flexibility and an expandable architecture, the system will enable instant access to up-to-date data from different institutions through Web services and meets the requirements of a real-time FFS. While the criteria requiring the expansion of the designed system were explained, its implementation was left for future studies.     

三峡区间入库洪水实时预报系统研究

三峡区间的数字流域水系模型采用基于格网型的数字高程模型坡面流模拟方法和处理"洼地"的最短流程法构建,并以新安江模型为基础建立具有诸多特点的三峡区间流域水文模型;以水动力学理论为基础建立考虑水利工程影响的河川型水库洪水演进模型,并实现这两者的有机耦合。在GIS平台上,将三峡区间流域水文模型、库区洪水演进模型和流域水系生成模型在底层集成,研制了功能先进和完善的三峡水库实时洪水预报系统。该系统已安装在三峡总公司梯级水库调度中心,投入试运行。     

半干旱地区洪水预报的若干问题

半干旱地区的特点是降水少且时空分布不均,下垫面条件也与湿润地区有很大不同,从而使洪水预报工作较为困难。其难点主要是:下渗能力分布不均;制约下渗率的表层土湿计算;河网汇流中的渗漏损失计算;降雨分布不均问题等。探讨了这些问题的解决办法。     

Real-time flood forecasting of the Tiber river in Rome

An adaptive, conceptual model for real-time flood forecasting of the Tiber river in Rome is proposed. This model simulates both rainfall-runoff transformations, to reproduce the contributions of 37 ungauged sub-basins that covered about 30% of the catchment area, and flood routing processes in the hydrographic network. The adaptive component of the model concerns the rainfall-runoff analysis: at any time step the whole set of the model parameters is recalibrated by minimizing the objective function constituted by the sum of the squares of the differences between observed and computed water surface elevations (or discharges). The proposed model was tested through application under real-time forecasting conditions for three historical flood events. To assess the forecasting accuracy, to support the decision maker and to reduce the possibility of false or missed warnings, confidence intervals of the forecasted water surface elevations (or discharges), computed according to a Monte Carlo procedure, are provided. The evaluation of errors in the prediction of peak values, of coefficients of persistence and of the amplitude of confidence intervals of prediction shows the possibility to develop a flood forecast model with a lead time of 12 h, which is useful for civil protection actions.     

复杂防洪系统联合优化调度模型

建立以水库群系统安全度最大、行蓄洪区系统损失最小为目标函数,将河道堤防安全行洪考虑为约束条件的复杂防洪系统多目标递阶优化调度模型(MoHOOM),以行蓄洪区总分洪流量为协调变量,将河道水流连续方程解耦,基于大系统分解协调法建立协调层和基于粒子群算法求解底层子系统优化问题,形成三级递阶分解协调结构和相应求解方法。以淮河中游防洪系统为背景进行了实例研究,给出了水库群泄流和行蓄洪区分洪最优方案,在相同初始计算条件下,优化模型结果比实际调度降低了鲇鱼山和梅山水库0.37和0.01的安全度指标,减小下游蒋家集和润河集河段超过安全泄量以上100 m3/s和720 m3/s的洪峰流量,启用南润段行洪区致损1 256.1万元;比规则调度降低了鲇鱼山和梅山水库0.24和0.21的安全度指标,减小下游蒋家集河段超过安全泄量以上750 m3/s的洪峰流量,避免南润段行洪区损失341.6万元。模型有利于挖掘上游水库群的防洪能力,在保障河道堤防安全行洪条件下,减少下游不必要的行蓄洪区分洪损失,以系统全局寻优方式进行复杂防洪系统联合调度。     

水库防洪优化调度的恒定出流模型及应用

现行水库洪水优化调度数学模型存在泄流闸门开度不断调整及时段间流量突变的问题。针对这些问题,将水库防洪优化调度数学模型分为时段内出库流量线性变化的瞬时出流模型和时段内出流不变的恒定出流模型。对于1个水库和1个防洪控制点所组成的基本防洪系统,应用矩形入流条件的河道洪水演进方法,以时段内恒定的出库流量为决策变量,构建水库防洪优化补偿调度数学模型。实例计算结果表明:恒定出流模型比瞬时出流模型占用的防洪库容减小0.05%~0.18%、最大下泄流量有增有减,即恒定出流模型既不劣于瞬时出流模型,也能很好地解决瞬时出流模型存在的问题。同时,实例揭示的水库二次补偿调节比等蓄量调度方式减小防洪库容10.6%,为确定水库的防洪库容提供了新的方法。     

Development of storm hyetographs for flood forecasting in the Kingdom of Saudi Arabia

This paper presents the derivation of the design storm hyetograph patterns for the Kingdom of Saudi Arabia based on real rainfall events from meteorological stations distributed throughout the Kingdom. Two thousand twenty-seven rainfall storms for a 20–28-year period were collected and analyzed covering 13 regions of the Kingdom. Four distinct dimensionless rainfall hyetograph patterns have been obtained over the Kingdom, while two patterns have been obtained for each individual region because of the lack of data for long-duration storms in individual regions. The resulting dimensionless rainfall patterns for each region can be used to develop storm hyetographs for any design duration, total rainfall depth and return period. It has been shown that the developed storm hyetographs have different features from other storm patterns that are commonly used in arid zones. The study recommends using these curves for the design of hydraulic structures in Kingdom of Saudi Arabia and regions alike.     

Waterflooding optimization with the INSIM-FT data-driven model

In a recent paper, we developed a physics-based data-driven model referred to as INSIM-FT and showed that it can be used for history matching and future reservoir performance predictions even when no prior geological model is available. The model requires no prior knowledge of petrophysical properties. In this work, we explore the possibility of using INSIM-FT in place of a reservoir simulation model when estimating the well controls that optimize water flooding performance where we use the net present value (NPV) of life-cycle production as our cost (objective) function. The well controls are either the flowing bottom-hole pressure (BHP) or total liquid rates at injectors and producers on the time intervals which represent the prescribed control steps. The optimal well controls that maximize NPV are estimated with an ensemble-based optimization algorithm using the history-matched INSIM-FT model as the forward model. We compare the optimal NPV obtained using INSIM-FT as the forward model with the estimate of the optimal NPV obtained using the correct full-scale reservoir simulation model when performing waterflooding optimization.     

A fuzzy neural network bagging ensemble forecasting model for 72-h forecast of low-temperature chilling injury

Natural Hazards - On the basis of the daily temperature and precipitation data of Guangxi and the NCEP/NCAR reanalysis data and forecast field data, the paper aims to determine the significant...     

Application of a triangular fuzzy AHP approach for flood risk evaluation and response measures analysis

Flood risk evaluation and prediction represents an essential analytic step to coherently link flood control and disaster mitigation. The paper established a hybrid evaluation model based on fuzzy analytic hierarchy process (AHP) and triangular fuzzy number. It comprises flood risk evaluation and prediction to obtain risk factors ranking and comprehensive flood risk prediction, and then analyzed flood risk response measures. A case study is proposed entailing a flood risk evaluation and prediction in the Lower Yangtze River region. The evaluation results showed that the proposed evaluation and prediction model was capable of adequately representing the actual setting. In addition, a comparison with the previously described AHP and trapezoidal fuzzy AHP, and experimental results are encouraging, which fully demonstrates the effectiveness and superiority of the proposed model.     

水库控制流域汛期分期的有效聚类分析

受诸多因素影响的水库汛期分期其实质是一个聚类数目未确知的高维时间序列聚类问题,它要求聚类方法具有能处理高维和时序性数据,且能同时回答聚为几类最为合理的能力。鉴于目前常规聚类方法不同时具备这些能力,在模糊C-均值聚类和紧密与分离聚类有效函数的基础上,提出了能够处理高维时序聚类问题的动态模糊C-均值聚类分析方法和相应的时序聚类有效性函数,耦合二者建立了适用于汛期分期的有效模糊聚类分析方法,提出采用实码加速遗传算法优化求解,克服了模糊C-均值聚类方法常规迭代优化求解对初值敏感的困难,并给出了完备的建模步骤和模型的合理性检验。最后,将模型应用于滦河流域潘家口水库汛期分期中,得出了合理的结论。